Re: lync and sync how to johnson 70vro
Seeing that you are from Ireland and the availability of a manual is probably scarce, I will give you the basic steps, the CONCEPT steps if you will, but you will have to examine your motor to see how these steps apply to your mechanism. This is involved, so bear with me, and if I miss something, well, you can refer to the book when you get it to correct it.
1. First step is usually to dis-engage the throttle linkage from the timing linkage. Separate the two mechanisms, so that the throttles are closed without any influence or pressure from the timing linkages. This is often done by backing off the roller that provides the cam action to move the throttle plates as the timing is advanced when applying throttle. You may actually have to disconnect a single rod linkage on your motor. But you will definitely see two distinct linkage mechanisms, one for the throttle, and one for the timing. Disconnect the throttle cable at the engine, too, as you do these steps.
2. Look on the starboard side for two adjustable screws with rubber bumpers on them. One is for idle stop, the other is for WOT stop. Adjust the idle stop so it barely touches the boss when all carbs are absolutely closed, adjust the WOT screw so that when at WOT, the throttle butterflies are open 90* to the venturi bores and no more.
3. Once the throttle is correct, re-connect the mechanism so the the two linkages (timing and throttle) are acting as one. Here it gets tricky. The roller that allows the "mechanical connection" of the throttle to timing linkages must be adjusted for proper "pick up point". Look your mechanism over to see how to adjust that roller. You will see various marks on the plastic, and maybe some on the metal block. Basically you want the two linkages to be in sync so that the roller lines up with the marks when at idle. I said it is different on all engines, so this is a point where you would best consult the book. Looking carefully you will see the marks.
4. You will find a screw somewhere on the linkage that controls the position of the timer base under the flywheel at idle. Turn that screw so that the timer base rotates forward or in a counterclockwise direction. Turn it a few turns, counting the turns so you can put it back if necessary. That is your idle speed adjustment, and if it idles too high, you turn the screw back so that the timer base rotates clockwise. No magic here, you are just moving the timer base under the flywheel to the optimum point for proper idle speed. Idle speed should be set in the water with exhaust back pressure. Usual idle speed is 650 to 700 in the water in forward gear.
5. You will find a screw with a rubber bumper on it under the flywheel (forward a bit) that controls the point where the timer base stops at WOT. This is a critical adjustment as too much advance will cause the engine to knock or ping (detonation) and do powerhead damage. Anyway, do a search on the Joe Reeves WOT timing procedure, and you can follow the instructions to statically set your WOT timing. Adjust the screw for proper WOT timing value as per the book. FOR EXAMPLE, on a 1979 V4 140 crossflow, the timing value is 28*BTDC at WOT. On a 1996 225 V6 looper, the timing is 18* BTDC at WOT. SO THEY ARE DIFFERENT FOR VARIOUS MOTORS. Use the proper timing value for your motor.
6. Hook up your throtttle cable properly. No pressure is allowed when hooked up. It should not press or pull in either direction when slipped over the connecting stud. Adjust the trunnion nut where the cable enters the lower cowl to make it right.
I am posting this to get you started. Look at the mechanism before you turn any screws. Grasp the concepts as they apply to your particular motor. Just study it as it moves as you advance the linkage by hand. You will see all these described functions and screw adjustments if you study the movement. Look at each step described above, and see how it applies to your motor before adjusting anything.
As JB said....get your manual ASAP. The manual will tell you exactly what to do, the order to do it, and the proper values for timing and idle speed. And if I missed a step, I apologize ahead of time.
